(1) Field of the Invention
The present invention relates to a loudspeaker system for mounting in a suspended ceiling comprising a support frame and back box assembly and a removable speaker cartridge.
(2) Background of the Invention
Suspended ceilings, consisting of ceiling tiles supported by a grid of t-bar frames, are common in business as well as in some residential environments. It is often desired to mount loudspeakers in suspended ceilings to provide for communications and/or entertainment. Consequently, various types of loudspeaker systems have been developed for installation in suspended ceilings.
One type of prior art ceiling loudspeaker system consists of a loudspeaker mounted to a conventional ceiling tile. A hole is cut in the ceiling tile to accommodate the speaker, and the speaker is mounted to the tile over, in, or adjacent to the hole. The size of speaker that can be used in this type of loudspeaker system is limited because conventional ceiling tiles have limited structural strength and in some cases are rated by the manufacturers as having no structural strength at all. FIG. 1 shows a modification of this type of ceiling loudspeaker system that adds a support frame that provides additional support for the loudspeaker. As shown in FIG. 1, the support frame includes support bars 105 and 110 that extend across the back of a ceiling tile 115 to t-bar frames (such as t-bar frame 120) that support the ceiling tile, and a support ring 125 that is mounted to support bars 105 and 110 adjacent to the hole 130 in ceiling tile 115. The speaker is mounted on support ring 125 so that some or all of the weight of the speaker is supported by the support bars and ring and not just the speaker tile, allowing a heavier speaker to be used. The speaker can be a single speaker or can be a speaker assembly that includes multiple speakers. A further modification of this type of ceiling loudspeaker system adds a metal “can” to the back of the speaker assembly that is intended to comply with fire codes for plenum installations.
An example of a ceiling speaker assembly that includes a back can and that is intended to be mounted in a ceiling tile using a support frame like that shown in FIG. 1 is the S126CT model ceiling speaker sold by Extron Electronics, which is shown in FIG. 2. As shown in FIG. 2, the S126CT ceiling speaker assembly 200 includes a woofer 205 with a coaxially mounted tweeter 210 mounted to a speaker frame 215. A metal back can 220 is mounted to the back of speaker frame 215 forming a chamber that encloses the back side of woofer 205. A removable panel in the back of metal back can 220 (not shown) provides access for electrical connections to the speaker unit. A crossover circuit may also be mounted to the rear of woofer 205. Internal speaker wires lead from the crossover circuit to each of woofer 205 and tweeter 210. To improve the acoustic response, a port 225 is formed in speaker frame 215. A plurality of mounting doglegs (sometimes referred to herein as “dogs” or “flip dogs”) 230 are attached to the rear of speaker frame 215. To mount speaker assembly 200 onto a ceiling tile, an appropriate hole is cut into the ceiling tile. A support frame such as that shown in FIG. 1 is installed on top of the ceiling tile. The rear of speaker assembly 200 is inserted into the hole in the ceiling tile from the bottom until speaker frame 215 is flush against the bottom surface of the ceiling panel. Mounting dogs 230 are then pivoted such that the ends of their doglegs are disposed over the support ring on the back side of the ceiling tile, thereby securing speaker assembly 200 to the ceiling tile and support frame.
Another type of ceiling speaker is a “lay-in” ceiling speaker, an embodiment of which is disclosed, for example, in U.S. Pat. No. 6,944,312 issued to Mason et al. entitled “Lay-In Ceiling Speaker.” The lay-in speaker disclosed in Mason et al. is intended to replace an entire ceiling tile. It consists of a speaker mounted to a perforated metal grille, which is crimped to a fiberglass back box, forming a generally rigid loudspeaker assembly that has the same lateral dimensions as a standard ceiling tile and that can be mounted in a suspended ceiling simply by removing an existing ceiling tile and putting the “lay-in” loudspeaker assembly in its place, the edges of the “lay-in” speaker resting on the t-bar support frames of a suspended ceiling in the same manner as a ceiling tile. When installed, the visual appearance of a lay-in speaker is that of a perforated grill having the size and shape of a ceiling tile.
Although lay-in speakers are easy to install, sometimes the visual appearance of a tile-mounted ceiling speaker is preferred over the appearance of a lay-in speaker. Until now, there has been no ceiling speaker assembly that combines the ease of installation of a lay-in speaker with the aesthetics of a tile-mounted ceiling speaker.